Portable electrical generators are specifically to be used outdoor, with warning labels and instructions that warn against use too close to a dwelling, in garages, or other protected areas where poisonous gasses can accumulate and enter an occupied dwelling. Further, portable electrical generator manufacturers warn against operating a portable electrical generator in an enclosed shed or other small enclosure because these kinds of environments restrict air flow around and through the unit and pose an overheating hazard. Finally, portable electrical generators cannot be exposed to rain, sleet, snow or ice, since wet conditions pose a risk of shock and electrocution. Many times it is during times of precipitation that a portable electrical generator is needed, and regardless of manufacturer warnings, portable electrical generator users take the risk to operate them in garages, on or under porches and in other covered or enclosed areas that can allow deadly gasses to infiltrate a dwelling or cause overheating. Portable electrical generator accidents often occur during times of bad weather, when the generator is most needed.
Some manufacturers, in addition to the Consumer Product Safety Commission, suggest that a generator can be safely used outdoors in inclement weather when under a portable pop-up canopy. In practice, this is a fundamentally unsound approach. Portable pop-up canopies are difficult to anchor, especially in frozen conditions or on driveways, they provide no protection to precipitation that is blown in from an angular direction, they cannot withstand moderate winds without collapsing or being blown away, and they are susceptible to collapse under the weight of moderate snow and ice.